Whirlpool has won anti-dumping judgements against LG and Samsung several times over the past few years.
In 2012 they won and "The U.S. plans to impose antidumping tariffs for Korean producers LG, Samsung, and Daewoo of 12.15 percent, 9.62 percent, and 79.11 percent, respectively."
This was on products imported from Mexico and South Korea.
To avoid these tariffs LG and Samsung moved production to China.
Whirlpool sued again in 2015.
I could not find an the exact article, but I believe these latest tariffs are a result of the court finding in favor of Whirlpool once again.
It made the news because it was Trump. When Obama did it, it was not news.